📄 compress.c
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}
}
/*---
Iterate up to BZ_N_ITERS times to improve the tables.
---*/
for (iter = 0; iter < BZ_N_ITERS; iter++) {
for (t = 0; t < nGroups; t++) fave[t] = 0;
for (t = 0; t < nGroups; t++)
for (v = 0; v < alphaSize; v++)
s->rfreq[t][v] = 0;
/*---
Set up an auxiliary length table which is used to fast-track
the common case (nGroups == 6).
---*/
if (nGroups == 6) {
for (v = 0; v < alphaSize; v++) {
s->len_pack[v][0] = (s->len[1][v] << 16) | s->len[0][v];
s->len_pack[v][1] = (s->len[3][v] << 16) | s->len[2][v];
s->len_pack[v][2] = (s->len[5][v] << 16) | s->len[4][v];
}
}
nSelectors = 0;
totc = 0;
gs = 0;
while (True) {
/*--- Set group start & end marks. --*/
if (gs >= s->nMTF) break;
ge = gs + BZ_G_SIZE - 1;
if (ge >= s->nMTF) ge = s->nMTF-1;
/*--
Calculate the cost of this group as coded
by each of the coding tables.
--*/
for (t = 0; t < nGroups; t++) cost[t] = 0;
if (nGroups == 6 && 50 == ge-gs+1) {
/*--- fast track the common case ---*/
register UInt32 cost01, cost23, cost45;
register UInt16 icv;
cost01 = cost23 = cost45 = 0;
# define BZ_ITER(nn) \
icv = mtfv[gs+(nn)]; \
cost01 += s->len_pack[icv][0]; \
cost23 += s->len_pack[icv][1]; \
cost45 += s->len_pack[icv][2]; \
BZ_ITER(0); BZ_ITER(1); BZ_ITER(2); BZ_ITER(3); BZ_ITER(4);
BZ_ITER(5); BZ_ITER(6); BZ_ITER(7); BZ_ITER(8); BZ_ITER(9);
BZ_ITER(10); BZ_ITER(11); BZ_ITER(12); BZ_ITER(13); BZ_ITER(14);
BZ_ITER(15); BZ_ITER(16); BZ_ITER(17); BZ_ITER(18); BZ_ITER(19);
BZ_ITER(20); BZ_ITER(21); BZ_ITER(22); BZ_ITER(23); BZ_ITER(24);
BZ_ITER(25); BZ_ITER(26); BZ_ITER(27); BZ_ITER(28); BZ_ITER(29);
BZ_ITER(30); BZ_ITER(31); BZ_ITER(32); BZ_ITER(33); BZ_ITER(34);
BZ_ITER(35); BZ_ITER(36); BZ_ITER(37); BZ_ITER(38); BZ_ITER(39);
BZ_ITER(40); BZ_ITER(41); BZ_ITER(42); BZ_ITER(43); BZ_ITER(44);
BZ_ITER(45); BZ_ITER(46); BZ_ITER(47); BZ_ITER(48); BZ_ITER(49);
# undef BZ_ITER
cost[0] = cost01 & 0xffff; cost[1] = cost01 >> 16;
cost[2] = cost23 & 0xffff; cost[3] = cost23 >> 16;
cost[4] = cost45 & 0xffff; cost[5] = cost45 >> 16;
} else {
/*--- slow version which correctly handles all situations ---*/
for (i = gs; i <= ge; i++) {
UInt16 icv = mtfv[i];
for (t = 0; t < nGroups; t++) cost[t] += s->len[t][icv];
}
}
/*--
Find the coding table which is best for this group,
and record its identity in the selector table.
--*/
bc = 999999999; bt = -1;
for (t = 0; t < nGroups; t++)
if (cost[t] < bc) { bc = cost[t]; bt = t; };
totc += bc;
fave[bt]++;
s->selector[nSelectors] = bt;
nSelectors++;
/*--
Increment the symbol frequencies for the selected table.
--*/
if (nGroups == 6 && 50 == ge-gs+1) {
/*--- fast track the common case ---*/
# define BZ_ITUR(nn) s->rfreq[bt][ mtfv[gs+(nn)] ]++
BZ_ITUR(0); BZ_ITUR(1); BZ_ITUR(2); BZ_ITUR(3); BZ_ITUR(4);
BZ_ITUR(5); BZ_ITUR(6); BZ_ITUR(7); BZ_ITUR(8); BZ_ITUR(9);
BZ_ITUR(10); BZ_ITUR(11); BZ_ITUR(12); BZ_ITUR(13); BZ_ITUR(14);
BZ_ITUR(15); BZ_ITUR(16); BZ_ITUR(17); BZ_ITUR(18); BZ_ITUR(19);
BZ_ITUR(20); BZ_ITUR(21); BZ_ITUR(22); BZ_ITUR(23); BZ_ITUR(24);
BZ_ITUR(25); BZ_ITUR(26); BZ_ITUR(27); BZ_ITUR(28); BZ_ITUR(29);
BZ_ITUR(30); BZ_ITUR(31); BZ_ITUR(32); BZ_ITUR(33); BZ_ITUR(34);
BZ_ITUR(35); BZ_ITUR(36); BZ_ITUR(37); BZ_ITUR(38); BZ_ITUR(39);
BZ_ITUR(40); BZ_ITUR(41); BZ_ITUR(42); BZ_ITUR(43); BZ_ITUR(44);
BZ_ITUR(45); BZ_ITUR(46); BZ_ITUR(47); BZ_ITUR(48); BZ_ITUR(49);
# undef BZ_ITUR
} else {
/*--- slow version which correctly handles all situations ---*/
for (i = gs; i <= ge; i++)
s->rfreq[bt][ mtfv[i] ]++;
}
gs = ge+1;
}
if (s->verbosity >= 3) {
VPrintf2 ( " pass %d: size is %d, grp uses are ",
iter+1, totc/8 );
for (t = 0; t < nGroups; t++)
VPrintf1 ( "%d ", fave[t] );
VPrintf0 ( "\n" );
}
/*--
Recompute the tables based on the accumulated frequencies.
--*/
/* maxLen was changed from 20 to 17 in bzip2-1.0.3. See
comment in huffman.c for details. */
for (t = 0; t < nGroups; t++)
BZ2_hbMakeCodeLengths ( &(s->len[t][0]), &(s->rfreq[t][0]),
alphaSize, 17 /*20*/ );
}
AssertH( nGroups < 8, 3002 );
AssertH( nSelectors < 32768 &&
nSelectors <= (2 + (900000 / BZ_G_SIZE)),
3003 );
/*--- Compute MTF values for the selectors. ---*/
{
UChar pos[BZ_N_GROUPS], ll_i, tmp2, tmp;
for (i = 0; i < nGroups; i++) pos[i] = i;
for (i = 0; i < nSelectors; i++) {
ll_i = s->selector[i];
j = 0;
tmp = pos[j];
while ( ll_i != tmp ) {
j++;
tmp2 = tmp;
tmp = pos[j];
pos[j] = tmp2;
};
pos[0] = tmp;
s->selectorMtf[i] = j;
}
};
/*--- Assign actual codes for the tables. --*/
for (t = 0; t < nGroups; t++) {
minLen = 32;
maxLen = 0;
for (i = 0; i < alphaSize; i++) {
if (s->len[t][i] > maxLen) maxLen = s->len[t][i];
if (s->len[t][i] < minLen) minLen = s->len[t][i];
}
AssertH ( !(maxLen > 17 /*20*/ ), 3004 );
AssertH ( !(minLen < 1), 3005 );
BZ2_hbAssignCodes ( &(s->code[t][0]), &(s->len[t][0]),
minLen, maxLen, alphaSize );
}
/*--- Transmit the mapping table. ---*/
{
Bool inUse16[16];
for (i = 0; i < 16; i++) {
inUse16[i] = False;
for (j = 0; j < 16; j++)
if (s->inUse[i * 16 + j]) inUse16[i] = True;
}
nBytes = s->numZ;
for (i = 0; i < 16; i++)
if (inUse16[i]) bsW(s,1,1); else bsW(s,1,0);
for (i = 0; i < 16; i++)
if (inUse16[i])
for (j = 0; j < 16; j++) {
if (s->inUse[i * 16 + j]) bsW(s,1,1); else bsW(s,1,0);
}
if (s->verbosity >= 3)
VPrintf1( " bytes: mapping %d, ", s->numZ-nBytes );
}
/*--- Now the selectors. ---*/
nBytes = s->numZ;
bsW ( s, 3, nGroups );
bsW ( s, 15, nSelectors );
for (i = 0; i < nSelectors; i++) {
for (j = 0; j < s->selectorMtf[i]; j++) bsW(s,1,1);
bsW(s,1,0);
}
if (s->verbosity >= 3)
VPrintf1( "selectors %d, ", s->numZ-nBytes );
/*--- Now the coding tables. ---*/
nBytes = s->numZ;
for (t = 0; t < nGroups; t++) {
Int32 curr = s->len[t][0];
bsW ( s, 5, curr );
for (i = 0; i < alphaSize; i++) {
while (curr < s->len[t][i]) { bsW(s,2,2); curr++; /* 10 */ };
while (curr > s->len[t][i]) { bsW(s,2,3); curr--; /* 11 */ };
bsW ( s, 1, 0 );
}
}
if (s->verbosity >= 3)
VPrintf1 ( "code lengths %d, ", s->numZ-nBytes );
/*--- And finally, the block data proper ---*/
nBytes = s->numZ;
selCtr = 0;
gs = 0;
while (True) {
if (gs >= s->nMTF) break;
ge = gs + BZ_G_SIZE - 1;
if (ge >= s->nMTF) ge = s->nMTF-1;
AssertH ( s->selector[selCtr] < nGroups, 3006 );
if (nGroups == 6 && 50 == ge-gs+1) {
/*--- fast track the common case ---*/
UInt16 mtfv_i;
UChar* s_len_sel_selCtr
= &(s->len[s->selector[selCtr]][0]);
Int32* s_code_sel_selCtr
= &(s->code[s->selector[selCtr]][0]);
# define BZ_ITAH(nn) \
mtfv_i = mtfv[gs+(nn)]; \
bsW ( s, \
s_len_sel_selCtr[mtfv_i], \
s_code_sel_selCtr[mtfv_i] )
BZ_ITAH(0); BZ_ITAH(1); BZ_ITAH(2); BZ_ITAH(3); BZ_ITAH(4);
BZ_ITAH(5); BZ_ITAH(6); BZ_ITAH(7); BZ_ITAH(8); BZ_ITAH(9);
BZ_ITAH(10); BZ_ITAH(11); BZ_ITAH(12); BZ_ITAH(13); BZ_ITAH(14);
BZ_ITAH(15); BZ_ITAH(16); BZ_ITAH(17); BZ_ITAH(18); BZ_ITAH(19);
BZ_ITAH(20); BZ_ITAH(21); BZ_ITAH(22); BZ_ITAH(23); BZ_ITAH(24);
BZ_ITAH(25); BZ_ITAH(26); BZ_ITAH(27); BZ_ITAH(28); BZ_ITAH(29);
BZ_ITAH(30); BZ_ITAH(31); BZ_ITAH(32); BZ_ITAH(33); BZ_ITAH(34);
BZ_ITAH(35); BZ_ITAH(36); BZ_ITAH(37); BZ_ITAH(38); BZ_ITAH(39);
BZ_ITAH(40); BZ_ITAH(41); BZ_ITAH(42); BZ_ITAH(43); BZ_ITAH(44);
BZ_ITAH(45); BZ_ITAH(46); BZ_ITAH(47); BZ_ITAH(48); BZ_ITAH(49);
# undef BZ_ITAH
} else {
/*--- slow version which correctly handles all situations ---*/
for (i = gs; i <= ge; i++) {
bsW ( s,
s->len [s->selector[selCtr]] [mtfv[i]],
s->code [s->selector[selCtr]] [mtfv[i]] );
}
}
gs = ge+1;
selCtr++;
}
AssertH( selCtr == nSelectors, 3007 );
if (s->verbosity >= 3)
VPrintf1( "codes %d\n", s->numZ-nBytes );
}
/*---------------------------------------------------*/
void BZ2_compressBlock ( EState* s, Bool is_last_block )
{
if (s->nblock > 0) {
BZ_FINALISE_CRC ( s->blockCRC );
s->combinedCRC = (s->combinedCRC << 1) | (s->combinedCRC >> 31);
s->combinedCRC ^= s->blockCRC;
if (s->blockNo > 1) s->numZ = 0;
if (s->verbosity >= 2)
VPrintf4( " block %d: crc = 0x%08x, "
"combined CRC = 0x%08x, size = %d\n",
s->blockNo, s->blockCRC, s->combinedCRC, s->nblock );
BZ2_blockSort ( s );
}
s->zbits = (UChar*) (&((UChar*)s->arr2)[s->nblock]);
/*-- If this is the first block, create the stream header. --*/
if (s->blockNo == 1) {
BZ2_bsInitWrite ( s );
bsPutUChar ( s, BZ_HDR_B );
bsPutUChar ( s, BZ_HDR_Z );
bsPutUChar ( s, BZ_HDR_h );
bsPutUChar ( s, (UChar)(BZ_HDR_0 + s->blockSize100k) );
}
if (s->nblock > 0) {
bsPutUChar ( s, 0x31 ); bsPutUChar ( s, 0x41 );
bsPutUChar ( s, 0x59 ); bsPutUChar ( s, 0x26 );
bsPutUChar ( s, 0x53 ); bsPutUChar ( s, 0x59 );
/*-- Now the block's CRC, so it is in a known place. --*/
bsPutUInt32 ( s, s->blockCRC );
/*--
Now a single bit indicating (non-)randomisation.
As of version 0.9.5, we use a better sorting algorithm
which makes randomisation unnecessary. So always set
the randomised bit to 'no'. Of course, the decoder
still needs to be able to handle randomised blocks
so as to maintain backwards compatibility with
older versions of bzip2.
--*/
bsW(s,1,0);
bsW ( s, 24, s->origPtr );
generateMTFValues ( s );
sendMTFValues ( s );
}
/*-- If this is the last block, add the stream trailer. --*/
if (is_last_block) {
bsPutUChar ( s, 0x17 ); bsPutUChar ( s, 0x72 );
bsPutUChar ( s, 0x45 ); bsPutUChar ( s, 0x38 );
bsPutUChar ( s, 0x50 ); bsPutUChar ( s, 0x90 );
bsPutUInt32 ( s, s->combinedCRC );
if (s->verbosity >= 2)
VPrintf1( " final combined CRC = 0x%08x\n ", s->combinedCRC );
bsFinishWrite ( s );
}
}
/*-------------------------------------------------------------*/
/*--- end compress.c ---*/
/*-------------------------------------------------------------*/
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